Table 4

Relative value of bedside screening tests of difficult intubation

Screening tests of difficult intubationNon-difficult intubation
(n=1733)
Difficult intubation
(n=276)
P valueSensitivity
(%, 95% CI)
Specificity
(%, 95% CI)
Positive predictive value
(%, 95% CI)
Negative predictive value
(%, 95% CI)
ROC area
(95% CI)
Upper airway obstruction, n (%)61 (4)28 (10)<0.00110 (7 to 14)97 (96 to 97)32 (22 to 42)87 (86 to 89)0.53 (0.52 to 0.55)
Known prior history of difficult airway150 (9)41 (15)0.00115 (11 to 20)91 (90.9 to 93)22 (16 to 28)87 (85 to 88)0.53 (0.51 to 0.55)
Micrognathia27 (2)12 (4)0.0024 (2 to 8)98 (98 to 99)31 (17 to 48)87 (85 to 88)0.51 (0.5 to 0.53)
Limited mouth opening262 (15)60 (21)0.00515 (14 to 17)78 (73 to 83)13 (11 to 15)81 (77 to 86)0.47 (0.44 to 0.49)
Limited neck extension27 (2)10 (4)0.024 (2 to 7)98 (98 to 99)27 (14 to 44)87 (85 to 88)0. 51 (0.49, 0.52)
Cleft palate17 (1)7 (3)0.033 (1 to 5)99 (98, 99.)29 (13 to 51)86 (85 to 88)0.51 (0.49 to 0.52)
Midfacial hypoplasia10 (<1)4 (1)0.12 (0.4 to 4)99 (98 to 99)29 (8 to 58)86 (85 to 88)0.5 (0.49 to 0.51)
Short thyromental distance250 (14)43 (16)0.614 (13 to 16)84 (80 to 88)14 (12 to 15)85 (81 to 89)0.49 (0.47 to 0.52)
  • ROC, receiver operator curve.